Struct tracing_core::stdlib::collections::linked_list::Cursor

pub struct Cursor<'a, T, A = Global>
where
    T: 'a,
    A: Allocator,
{
    index: usize,
    current: Option<NonNull<Node<T>>>,
    list: &'a LinkedList<T, A>,
}

🔬This is a nightly-only experimental API. (linked_list_cursors #58533)

A cursor over a LinkedList.

A Cursor is like an iterator, except that it can freely seek back-and-forth.

Cursors always rest between two elements in the list, and index in a logically circular way. To accommodate this, there is a “ghost” non-element that yields None between the head and tail of the list.

When created, cursors start at the front of the list, or the “ghost” non-element if the list is empty.

Fields

index: usize

🔬This is a nightly-only experimental API. (linked_list_cursors #58533)

current: Option<NonNull<Node<T>>>

🔬This is a nightly-only experimental API. (linked_list_cursors #58533)

list: &'a LinkedList<T, A>

🔬This is a nightly-only experimental API. (linked_list_cursors #58533)

Implementations

impl<'a, T, A> Cursor<'a, T, A>

where A: Allocator,

pub fn index(&self) -> Option<usize>

🔬This is a nightly-only experimental API. (linked_list_cursors #58533)

Returns the cursor position index within the LinkedList.

This returns None if the cursor is currently pointing to the “ghost” non-element.

pub fn move_next(&mut self)

🔬This is a nightly-only experimental API. (linked_list_cursors #58533)

Moves the cursor to the next element of the LinkedList.

If the cursor is pointing to the “ghost” non-element then this will move it to the first element of the LinkedList. If it is pointing to the last element of the LinkedList then this will move it to the “ghost” non-element.

pub fn move_prev(&mut self)

🔬This is a nightly-only experimental API. (linked_list_cursors #58533)

Moves the cursor to the previous element of the LinkedList.

If the cursor is pointing to the “ghost” non-element then this will move it to the last element of the LinkedList. If it is pointing to the first element of the LinkedList then this will move it to the “ghost” non-element.

pub fn current(&self) -> Option<&'a T>

🔬This is a nightly-only experimental API. (linked_list_cursors #58533)

Returns a reference to the element that the cursor is currently pointing to.

This returns None if the cursor is currently pointing to the “ghost” non-element.

pub fn peek_next(&self) -> Option<&'a T>

🔬This is a nightly-only experimental API. (linked_list_cursors #58533)

Returns a reference to the next element.

If the cursor is pointing to the “ghost” non-element then this returns the first element of the LinkedList. If it is pointing to the last element of the LinkedList then this returns None.

pub fn peek_prev(&self) -> Option<&'a T>

🔬This is a nightly-only experimental API. (linked_list_cursors #58533)

Returns a reference to the previous element.

If the cursor is pointing to the “ghost” non-element then this returns the last element of the LinkedList. If it is pointing to the first element of the LinkedList then this returns None.

pub fn front(&self) -> Option<&'a T>

🔬This is a nightly-only experimental API. (linked_list_cursors #58533)

Provides a reference to the front element of the cursor’s parent list, or None if the list is empty.

pub fn back(&self) -> Option<&'a T>

🔬This is a nightly-only experimental API. (linked_list_cursors #58533)

Provides a reference to the back element of the cursor’s parent list, or None if the list is empty.

pub fn as_list(&self) -> &'a LinkedList<T, A>

🔬This is a nightly-only experimental API. (linked_list_cursors #58533)

Provides a reference to the cursor’s parent list.

Trait Implementations

impl<T, A> Clone for Cursor<'_, T, A>

where A: Allocator,

fn clone(&self) -> Cursor<'_, T, A>

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T, A> Debug for Cursor<'_, T, A>

where T: Debug, A: Allocator,

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<T, A> Send for Cursor<'_, T, A>

where T: Sync, A: Allocator + Sync,

impl<T, A> Sync for Cursor<'_, T, A>

where T: Sync, A: Allocator + Sync,